The electronic structure of the bis(dioxolene) bridging ligand -- is responsive to metal-ligand magnetic exchange coupling. Comparison of the crystal structure of to that of indicates an open-shell biradical ground state for the dinuclear Ni(II) complex compared to the closed-shell quinoidal character found in the dinuclear Zn(II) complex. Consistent with a comparison of bond lengths obtained by X-ray diffraction, the analysis of the variable-temperature magnetic susceptibility data for crystalline yields reduced SQ-SQ radical-radical magnetic exchange coupling ( = -203 cm) compared to that of ( = -321 cm).
View Article and Find Full Text PDFA series of oligothiophene bis(dioxolene) complexes, SQ-Th-SQ (SQ = = ½TpZn(3--butyl-orthosemiquinonate); Tp = tris(5-cumenyl-3-methylpyrazolyl)borate anion) have been synthesized, structurally characterized, and studied as a function of the number of thiophene bridging units, ( = 0-3) using a combination of variable-temperature (VT) electronic absorption and EPR spectroscopies, and VT magnetic susceptibility measurements. The thiophene bridge bond lengths determined by X-ray crystallography display dramatic differences across the SQ-Th-SQ series. Bridge bond deviation values (Σ||) display a progressive change in the nature of the bridge fragment bonding as the number of thiophene groups increases, with quinoidal bridge character for = 1 (SQ-Th-SQ) and biradical character with "aromatic" bridge bond lengths for = 3 (SQ-Th-SQ).
View Article and Find Full Text PDFA major complication of chronic kidney disease is the derangement of mineral metabolism, leading to increased risk of fractures and cardiovascular mortality. Current therapeutic regimens are focused on reducing parathyroid hormone levels caused by secondary hyperparathyroidism, and the active vitamin D metabolite l,25(OH)D, with limited success. It may be a more effective approach, however, if we could target the delayed response of parathyroid hormone in the early retention of phosphate following loss of renal function.
View Article and Find Full Text PDFThe 22 Annual Santa Fe Bone Symposium (SFBS) was a hybrid meeting held August 5-6, 2022, with in-person and virtual attendees. Altogether, over 400 individuals registered, a majority of whom attended in-person, representing many states in the USA plus 7 other countries. The SFBS included 10 plenary presentations, 2 faculty panel discussions, satellite symposia, Bone Health & Osteoporosis Foundation Fracture Liaison Service Boot Camp, and a Project ECHO workshop, with lively interactive discussions for all events.
View Article and Find Full Text PDFPatients with osteoporosis and chronic kidney disease (CKD) are at increased risk of fracture and associated negative outcomes, including increased mortality. The present post hoc analysis of two randomized, multicenter, phase 3 clinical trials-Fracture Study in Postmenopausal Women with Osteoporosis (FRAME) and Active-Controlled Fracture Study in Postmenopausal Women with Osteoporosis at High Risk (ARCH)-investigated the efficacy and safety of romosozumab in postmenopausal women with osteoporosis and mild-to-moderate CKD. The analysis included data from 7147 patients from FRAME and 4077 from ARCH.
View Article and Find Full Text PDFThe 2021 Virtual Santa Fe Bone Symposium was held August 5-8, with over 300 registered attendees from throughout the USA, and at least 18 other countries. This annual meeting focuses on applying advances in basic science and clinical research to the care of patients with osteoporosis and those with inherited and acquired disorders of bone metabolism. Participants represented a broad range of medical disciplines with an interest in skeletal diseases.
View Article and Find Full Text PDFCleve Clin J Med
September 2021
Am J Kidney Dis
October 2021
Osteoporosis is defined as a skeletal disorder of compromised bone strength predisposing those affected to an elevated risk of fracture. However, based on bone histology, osteoporosis is only part of a spectrum of skeletal complications that includes osteomalacia and the various forms of renal osteodystrophy of chronic kidney disease-mineral and bone disorder (CKD-MBD). In addition, the label "kidney-induced osteoporosis" has been proposed, even though the changes caused by CKD do not qualify as osteoporosis by the histological diagnosis.
View Article and Find Full Text PDFBackground And Objective: Abaloparatide, an anabolic osteoporosis treatment administered by subcutaneous (SC) injection, increases bone mineral density (BMD) and reduces fracture risk in postmenopausal women with osteoporosis. The abaloparatide-solid Microstructured Transdermal System [abaloparatide-sMTS (Kindeva, St Paul, MN, USA)], which delivers abaloparatide intradermally, is in development to provide an alternative method for abaloparatide delivery. The objective of this study was to evaluate the ability of subjects to self-administer abaloparatide-sMTS, based on pharmacokinetic and pharmacodynamic markers.
View Article and Find Full Text PDFAnabolic osteoporosis drugs improve bone mineral density by increasing bone formation. The objective of this study was to evaluate the early effects of abaloparatide on indices of bone formation and to assess the effect of abaloparatide on modeling-based formation (MBF), remodeling-based formation (RBF), and overflow MBF (oMBF) in transiliac bone biopsies. In this open-label, single-arm study, 23 postmenopausal women with osteoporosis were treated with 80 μg abaloparatide daily.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
January 2021
Context: The effects of long-term exposure to denosumab in individuals with renal insufficiency are unknown.
Objective: This post hoc analysis evaluates the long-term safety and efficacy of denosumab in individuals with mild-to-moderate chronic kidney disease (CKD) (stages 2 and 3) using data from the pivotal phase 3, double-blind, 3-year FREEDOM (NCT00089791) and open-label, 7-year extension (NCT00523341) studies.
Participants And Methods: Women age 60 to 90 years with a bone mineral density (BMD) T-score of less than -2.
Objective: Fractures due to osteoporosis represent a serious burden on patients and healthcare systems. The objective of this review is to provide an overview of the anabolic agent abaloparatide (ABL) for the treatment of postmenopausal women with osteoporosis at high risk for fracture.
Methods: A literature review was conducted using PubMed to identify articles focused on ABL published prior to February 10, 2020, using the search term "abaloparatide".
J Bone Miner Res
December 2020
Chronic kidney disease (CKD) disturbs mineral homeostasis, leading to mineral and bone disorders (MBD). CKD-MBD is a significant problem and currently available treatment options have important limitations. Phosphate retention is thought to be the initial cause of CKD-MBD but serum phosphate remains normal until the late stages of CKD, due to elevated levels of the phosphaturic hormone fibroblast growth factor-23 (FGF-23), and parathyroid hormone (PTH).
View Article and Find Full Text PDFThe 3-year placebo-controlled FREEDOM (Fracture REduction Evaluation of Denosumab in Osteoporosis Every 6 Months) trial established the antifracture efficacy of denosumab in postmenopausal women with osteoporosis. The 7-year open-label extension demonstrated that denosumab treatment for up to 10 years was associated with low rates of adverse events and low fracture incidence. The extension lacked a long-term control group, thus limiting the ability to fully evaluate long-term efficacy.
View Article and Find Full Text PDFType 2 diabetes mellitus (T2DM) increases fracture risk despite normal or increased BMD. Abaloparatide reduces fracture risk in patients with postmenopausal osteoporosis (PMO); however, its efficacy in women with T2DM is unknown. This post hoc analysis evaluated the efficacy and safety of abaloparatide in patients with T2DM.
View Article and Find Full Text PDFBone
May 2020
Etidronate is a non-nitrogen-containing bisphosphonate. Because it binds with calcium and inhibits crystal formation and dissolution, it was considered by Procter & Gamble as an additive to toothpaste (to prevent build-up of tartar) and detergent (to bind calcium and increase sudsing in "hard" water). The first clinical use (1968) was for fibrodysplasia ossificans progressiva.
View Article and Find Full Text PDFAbaloparatide is a selective activator of the parathyroid hormone type 1 receptor signaling pathway that favors the stimulation of bone formation. Here, we report a prospective, exploratory analysis of bone mineral density (BMD) response rates comparing sequential abaloparatide/alendronate vs placebo/alendronate across the ACTIVE and ACTIVExtend studies. BMD was measured at the lumbar spine, total hip, and femoral neck from the beginning of ACTIVE to the end of ACTIVExtend (18 months of abaloparatide or placebo followed by about 1 month for re-consent, followed by 24 months of alendronate treatment for a total of 43 months).
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